diff options
Diffstat (limited to 'src/script')
| -rw-r--r-- | src/script/sign.cpp | 16 | ||||
| -rw-r--r-- | src/script/sign.h | 2 |
2 files changed, 17 insertions, 1 deletions
diff --git a/src/script/sign.cpp b/src/script/sign.cpp index e7bb90daa3..1982e8a832 100644 --- a/src/script/sign.cpp +++ b/src/script/sign.cpp @@ -244,17 +244,33 @@ bool SignPSBTInput(const SigningProvider& provider, const CMutableTransaction& t input.FillSignatureData(sigdata); // Get UTXO + bool require_witness_sig = false; CTxOut utxo; if (input.non_witness_utxo) { + // If we're taking our information from a non-witness UTXO, verify that it matches the prevout. + if (input.non_witness_utxo->GetHash() != tx.vin[index].prevout.hash) return false; + // If both witness and non-witness UTXO are provided, verify that they match. This check shouldn't + // matter, as the PSBT deserializer enforces only one of both is provided, and the only way both + // can be present is when they're added simultaneously by FillPSBT (in which case they always match). + // Still, check in order to not rely on callers to enforce this. + if (!input.witness_utxo.IsNull() && input.non_witness_utxo->vout[tx.vin[index].prevout.n] != input.witness_utxo) return false; utxo = input.non_witness_utxo->vout[tx.vin[index].prevout.n]; } else if (!input.witness_utxo.IsNull()) { utxo = input.witness_utxo; + // When we're taking our information from a witness UTXO, we can't verify it is actually data from + // the output being spent. This is safe in case a witness signature is produced (which includes this + // information directly in the hash), but not for non-witness signatures. Remember that we require + // a witness signature in this situation. + require_witness_sig = true; } else { return false; } MutableTransactionSignatureCreator creator(&tx, index, utxo.nValue, sighash); + sigdata.witness = false; bool sig_complete = ProduceSignature(provider, creator, utxo.scriptPubKey, sigdata); + // Verify that a witness signature was produced in case one was required. + if (require_witness_sig && !sigdata.witness) return false; input.FromSignatureData(sigdata); return sig_complete; } diff --git a/src/script/sign.h b/src/script/sign.h index 24cddda51b..d2033af731 100644 --- a/src/script/sign.h +++ b/src/script/sign.h @@ -678,7 +678,7 @@ bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreato bool SignSignature(const SigningProvider &provider, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, const CAmount& amount, int nHashType); bool SignSignature(const SigningProvider &provider, const CTransaction& txFrom, CMutableTransaction& txTo, unsigned int nIn, int nHashType); -/** Signs a PSBTInput */ +/** Signs a PSBTInput, verifying that all provided data matches what is being signed. */ bool SignPSBTInput(const SigningProvider& provider, const CMutableTransaction& tx, PSBTInput& input, SignatureData& sigdata, int index, int sighash = 1); /** Extract signature data from a transaction input, and insert it. */ |